Evidence from a study of two sharks indicates that they may have been infected, according to the preliminary Fish and Game findings released by Redwood City:

“The Fish were found to have inflammation, bleeding, and lesions in the brain, and hemorrhaging from the skin near vents and, in the female fish sample, hemorrhaging in and around various internal organs. A microscopic tissue analysis is underway, along with study of possible bacterial infection.”

More lab work is underway in the effort to identify the cause of the bleeding.

Meanwhile, two more sharks were spotted near San Francisco International Airport Thursday, bringing the total number of dead sharks found on the Peninsula in recent weeks to at least 50.

Redwood City said tests indicate that water quality in the town’s channels and waterways is not dangerous, and the fact that the sharks are turning up elsewhere suggests there may be another cause.

(Copyright 2011 by CBSSan Francisco. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. Wire services may have contributed to this report.)